X-ray absorption spectra of chlorine K edge, ruthenium LIII edge, and rhodium LIII edge from (NH4)3[RhCl6], K3[RuCl6], and [Ru(NH3)6]Cl3 have been measured with a Johann-type 50 cm bent crystal vacuum spectrograph. The white lines due to the transitions to the incompletely filled antibonding molecular orbital (MO) 2t2g(π*) or nonbonding orbital t2g and the empty antibonding MO 3eg(σ*) for the octahedral complexes have been observed in the Cl K edge, Ru LIII edge, and Rh LIII edge regions. It is found that the two absorption peaks at the Ru LIII edge reflect the ligand-field effect. An interpretation for experimental results of the Cl K edge and the Ru LIII edge absorption spectra in K3RuCl6 on the basis of the MO scheme leads us to the conclusion that the white lines at the Cl K edge suffer from the effect of core hole.

No abstract

No abstract

No abstract

Abstract-It is experimentally verified that a synchroscan streak camera, incorporating a microchannel plate and synchronizing with UV picosecond pulses generated inside the cavity of a mode-locked CW ring dye laser, has enough sensitivity to detect picosecond emission phenomena in the region ofasingle-photon event. To demonstrate the usefulness of the synchroscan streak camera, the first measurement of time-and wavelength-resolved emissions in the picosecond region is successfully carried out for adenine and polyadenylic acid aqueous solutions at room temperature, and shows that their shortest lifetimes, due to the monomer fluorescence, are 6 and 8 ps, respectively.F OR a study on nucleic acid photochemistry and photobiology, it is essential to make clear the dynamic behavior of the luminescence from nucleic acid bases in mononers, polymers, and higher order structures. photon counting method. They found that the emission quantum yields of adenine and polyadenylic acid were 2.4 X and 3 X respectively [3 J . The lifetime of polyadenylic acid depended on the wavelength of the emission band, and the origin of more than three emission components was discussed 131. However, the questions still remain because of the instrumental restriction of the time resolution. Therefore, further investigation based on time-and wavelength-resolved emission measurements in the picosecond time region is strongly needed.An electron-optical streak camera in synchronous operation with a mode-locked CW dye laser has become the most useful instrument that can directly measure the time and wavelength versus the intensity profile of a picosecond optical event for the weak luminescence [5], [6]. Using a highly-sensitive synchroscan streak camera with a mode-locked and internally frequency-doubled CW ring dye laser, we report the first direct